package com.regiee.filter;

import com.alibaba.fastjson.JSON;
import com.regiee.common.BaseContext;
import com.regiee.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/*
检查用户是否已经完成登录
 */
@Slf4j
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符写法
    public static final AntPathMatcher PATH_MATCHER=new AntPathMatcher();
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse
            servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request=(HttpServletRequest) servletRequest;
        HttpServletResponse response=(HttpServletResponse) servletResponse;
        //获取本次的url
        String requestUrl=request.getRequestURI();
        log.info("拦截到请求{}",requestUrl);
        String[] urls=new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "common/**"
        };
        //判断本次请求是否需要处理
        boolean check=check(urls,requestUrl);
        //如果不需要处理，直接放行
        if(check){
            log.info("本次请求{}不需要处理",requestUrl);
            filterChain.doFilter(request,response);
            return;
        }
        //判断登录状态，如果已经登录，就放行
        if(request.getSession().getAttribute("employee")!=null){
            log.info("用户已登录,用户ID为:{}",request.getSession().getAttribute("employee"));
            Long id=(Long)request.getSession().getAttribute("employee");
            /*
            将登录用户的id放在ThreadLocal线程存储空间中
             */
            BaseContext.setThreadLocal(id);
            filterChain.doFilter(request,response);
            return;
        }
        log.info("用户未登录");
        //如果没有登录，就返回没有登录的结果，通过输出流的方式向客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }
    /*
    路径匹配，检查本次路径是否需要处理
     */
    public boolean check(String [] urls,String requestUrl){
        for(String url:urls){
            if(PATH_MATCHER.match(url,requestUrl)){
                return true;
            }
        }
        return false;
    }
}
